1. Field of the Invention
The invention relates generally to an apparatus for treating surfaces of wafer-shaped articles, such as semiconductor wafers, wherein one or more treatment fluids may be recovered from within a closed process chamber.
2. Description of Related Art
Semiconductor wafers are subjected to various surface treatment processes such as etching, cleaning, polishing and material deposition. To accommodate such processes, a single wafer may be supported in relation to one or more treatment fluid nozzles by a chuck associated with a rotatable carrier, as is described for example in U.S. Pat. Nos. 4,903,717 and 5,513,668.
Alternatively, a chuck in the form of a ring rotor adapted to support a wafer may be located within a closed process chamber and driven without physical contact through an active magnetic bearing, as is described for example in International Publication No. WO 2007/101764 and U.S. Pat. No. 6,485,531.
For many applications the closed process chamber needs to be purged with ozone or an inert gas such as nitrogen, prior to commencement of a given process, or between successive processes. Additionally, for many applications the process chambers also need to be cleaned, for example by rinsing with deionized water.
An improved design for closed chamber single wafer wet processing is described in commonly-owned copending application U.S. Pub. No. 2013/0134128, in which the lid for the chamber is equipped with a fluid distribution ring that is either resilient or maintained at a very small gap from the edge of the surrounding chamber wall. However, it has proven difficult in practice to assemble the chamber without damaging the edge of the annular gap. Moreover, when the ring is made of a resilient material, it has been found that such material may expand during high temperature processing, thereby causing the gap to close partially and impair the purging function.